In cryogenics two embrittlement mechanisms do occur, low temperature embrittlement and hydrogen embrittlement.
Low temperature embrittlement does affect most materials more or less pronounced. It causes overloaded components to fracture spontaneously rather than accommodating the stress by plastic deformation. The picture shows a fractured fitting whose material was not suitable for low temperatures.
If hydrogen is present during the production of materials or if components come into contact with hydrogen in operation, then hydrogen embrittlement can occur under certain conditions. As the mechanisms of hydrogen embrittlement are not yet fully understood, special caution must be applied. Literature [4,5,6].